White-tailed deer can jump almost eight feet high, so effective upright fences against them should be this high. Deer may be able to jump high, but not both high and over a distance. So a fence may not be as high, perhaps six feet, but slanted outward. The deer will try walking under the fence and meet resistance.Make sure your fence is too tall for deer to jump over. Depending on the variety of deer you have in your garden, your fence needs to be high enough that deer .